relax SVN archive

Initialized merge tracking via "svnmerge" with revisions "1-15167" from
svn+ssh://bugman@.../svn/relax/branches/spec_api

Initialized merge tracking via "svnmerge" with revisions "1-15166" from
svn+ssh://bugman@.../svn/relax/1.3

Fixes for all of the value.set user function back end unit tests.

The parameter names are now regularised.

Added the api_objects module to the package __all__ list.

Fix for the specific API common _default_value_spin() method.

The value is now returned!

Fix for the model-free specific API default_value() method.

Reintroduced the specific API default_value() method to most of the analyses.

Mass conversion to the new GLOBAL_PARAMS and SPIN_PARAMS specific API data structures.

This involves mainly the conversion of the model-free analysis to these new objects, and the
subsequent changes to how model-free parameters are handled. The parameters are now all lowercase,
for example ['S2', 'te', 'Rex'] is now ['s2', 'te', 'rex']. The follow parameters are now converted
throughout relax:
'bond_length' to 'r',
'CSA' to 'csa',
'heteronucleus' to 'heteronuc_type',
'proton' to 'proton_type'.

The regularisation of the specific analysis parameters via GLOBAL_PARAMS and SPIN_PARAMS has
significantly simplified the current code and make it much easier to introduce new analyses.

Fix for the specific API common method _return_value_general() for when spectrum IDs are not present.

Not sure why this change is necessary! This could introduce future bugs, or hide a new bug!

Updated the arg_check.is_func() function for handling class methods.